Due to military build-up, shelf-life expiration and technical advances, munitions are becoming obsolete or in excess of a quantity desired to be kept in reserve. This presents a need to disarm and recover salvageable material of munitions. For example, for munitions such as grenades, there is a need to recover the grenades and remove the lead charge, explosive and cone liner from the grenade, leaving a recovered grenade casing.
Demilitarization programs have been in operation to disarm and recover salvageable material of artillery rounds loaded with munitions, including M42, M46, M77 and M80 general purpose type grenades. Typically, the fuse housing and fuse slider are secured to prevent the fuse slider from moving into an armed position. Next, a hole (typically ⅜ of an inch in diameter) is mechanically punched through the grenade casing where the flange of a cone-shaped liner is attached to the interior of the casing, deforming the liner and exposing the explosive charge inside the grenade. The explosive charge (also referred to simply as explosive) in the grenade is then burned away in a controlled burning apparatus known as an Explosive Waste Incinerator (EWI) or, alternatively, the entire grenade assemblies are mass detonated on a controlled demolition field.
There are several disadvantages of these prior art methods. None of the explosive material is salvaged. The EWI process takes a long time to burn away the entire explosive, and must be carefully controlled to minimize high order detonation explosive burning. Moreover, the burning away of the explosive produces toxic fumes in the EWI which must be contained and detoxified. Thus, this prior art method contributes to high operating cost, high equipment maintenance cost and does not salvage any of the explosive material. Also, after mass detonations there is potential for ground water and air contamination.
Day & Zimmermann, Inc. disclosed a better approach for removing the explosive charge from the grenade by removing most of the explosive before the EWI. In U.S. Pat. No. 5,974,937, entitled Method and System for Removing an Explosive Charge From a Shaped Charged Munition, and issued Nov. 2, 1999, the contents of which are incorporated by reference herein in their entirety, a hollow punch die is inserted through an open end of the grenade casing to gouge the cone out of the assembly and remove (e.g., drill or punch) most of the explosives out of the casing. The removed explosive can then be salvaged for use in commercial demolition charges and the EWI processing can be performed at higher pass through rates and with less toxic fumes and residue. However, this improved process leaves a significant amount of explosives inside the body, since, due to safety considerations, the die or drill must not come in contact with the metal components. Therefore, the EWI processing is still required to remove the residual explosives, producing toxic fumes and residue. While the improved approach is effective as a demil operation, it reduces the opportunity to reclaim the casing and liner for subsequent reuse and requires an incinerator to complete the explosive removal process.
The present inventor realized that it would be even more beneficial to develop an approach that safely removes the lead charge, substantially all of the explosive, and the cone-shaped liner from the munition body (e.g., casing). Recovered munition or grenade bodies can then be reused for new production or reclaimed and recycled as scrap metal. Explosives can be reused for ammunition or sold for mining operation. The cones, typically copper, can be sold as scrap.